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Tuesday, December 9, 2014

The Greenhouse in Midwinter

Saturday seemed like the darkest day of the year. Ten hours of twilight followed by fourteen hours of night. Outside was a warm blanket of fog. Inside the greenhouse, the plants yawned and went back to sleep. But not our tiny Ida lata. It glowed like a candelabra.

I admit I have kind of a thing for this genus, the former Lycaste species from South America now properly called Sudamerlycaste. I love the subtle ivory and olive color. And that fringe. Sudamerlycaste is a genus for connoisseurs of lip fringe.

Sudamerlycaste fimbriata has a more robust flower, about four inches from top to bottom, with a nice sawtooth fringe. It's a ghostly presence in our dark greenhouse.

Many of the Sudamerlycaste species are suited to a cool greenhouse, but ours are, for the present, tolerating intermediate temperatures (60º-ish night minimum), probably because the last two summers have been uncharacteristically cool. We grow our plants in a mixture of premium long-fibered sphagnum and coarse chopped tree fern fiber.

Monday, November 24, 2014

Pescatoria lehmannii

The phrase 'beautiful orchid' invariably conjures in my mind an image of this particular species.

It's not just the blue-violet perianth or the creamy citrus scent. On top of everything else, it's that lip, thickly carpeted with hairs, that makes Pescatoria* lehmannii extraordinary to me. That combination of beauty and quirkiness is irresistible.

So what's up with that lip, anyway?  Let's remove the petals and sepals and have a closer look.
Dorsal view. Pointing directly at us is the column and below it is that impressively hairy lip.

Turning the flower on its side, you can see that the lip has a distinctive raised thickening, or callus, at its base. The callus has ribs, called keels.

Dorsal view again, this time with the column removed. With the column removed you can get a better look at the base of the lip and the callus. The base of the lip has a deep opening outlined by the callus. In Pescatoria lehmannii the interior outline of the callus is an inverted M.

Turning the lip over to view its ventral surface, you can see that the lip actually has two side lobes rolled backward. At the base of the lip is the narrow claw, which joins the lip to the base of the column.
Here's the column in ventral view. Some pescatorias (the former Bollea species) have a column with lateral wings. Pescatoria lehmannii has a wingless column.

We grow Pescatoria lehmannii in a greenhouse with intermediate temperatures, 85% relative humidity and 80 % shade. It does well for us in a mixture of premium sphagnum and coarse shredded tree fern fiber. Since pescatorias (all Zygopetalinae, actually) hate root disturbance, I prefer to grow them in cedar baskets rather than plastic containers. After about three years, the basket disintegrates and becomes easy to remove with minimal root disturbance.

*I've updated the spelling of this genus to make it consistent with the International Plant Names Index.

Saturday, November 15, 2014

Behind the Scenes at Garden Lights Holiday Nights

This week, as we raced to put the finishing touches on our Garden Lights Holiday Nights display (opening tonight!), I paused to snap a few pictures for you.

In the Conservatory Lobby, Sarah and Jason installed Freedom Red Poinsettias and variegated Spider Plants on the vertical wall.

...and Dendrobium Mini Snowflake on wave stands in front of the vertical wall. Radiant light orbs float overhead.

In the Orchid Atrium a non-traditional holiday color palette -chartreuse, pink and soft blue -is new this year, the brilliant inspiration of our Landscape Design Manager, Tres Fromme, who designs all of our seasonal displays.

It's seventeen feet to the top. Jason, Matt and Sarah installed Jubilee Pink Poinsettias and Dracaena Lemon Lime on our Poinsettia tree.

Megan engulfed in a sea of pink Kalanchoe, Echeveria Big Blue, Dracaena Limelight and Sansevieria Moonshine.

Garden Lights Holiday Nights opens at 5 pm tonight. This is our biggest and best holiday show ever, so don't miss it!

Friday, November 7, 2014

Bucket Orchid Season

Our Bucket Orchids (Coryanthes) are producing a lovely autumnal flush of growth. Some pretty incredible flowers will follow in a couple of months. Here's one of the earliest, Coryanthes mastersiana.

Coryanthes mastersiana produces two to three flowers on each inflorescence. It somewhat resembles the Brazilian species Coryanthes speciosa, but the fragrance is very different. According to Günter Gerlach's website, Coryanthes mastersiana grows together with Coryanthes flava and Coryanthes elegantium in western Colombia and Ecuador.

Above is a diagram to help you make sense of the peculiar anatomy of Coryanthes flowers. The lip, often the most elaborate of an orchid's three petals, is modified in Coryanthes to facilitate pollination. The bucket, or epichile, fills with liquid from two glands protruding from sides of the column. At the rear of the bucket, and just visible in the photo, is an opening where the bucket meets the anther cap at the apex of the column.

When a male Euglossine bee scratches the surface of the hypochile in order to obtain liquid fragrance, he slips into the bucket. With his wings drenched, his only escape is to paddle to the rear opening and force his way through the small opening. In doing so, he rubs up against the sticky end of the pollinarium, which ends up attached to his body. At a subsequent Coryanthes the process is repeated, but this time he leaves the pollinia behind on the stigmatic surface of the column.

Coryanthes produce some of the most incredible flowers in the entire orchid family and this year I plan to set more capsules on our plants.

Monday, November 3, 2014


Here's a mystery for you. The lovely Tulip Orchid pictured above we received as Anguloa x ruckeri, a hybrid between Anguloa clowesii and Anguloa hohenlohii. Looks to me like there may be something else, perhaps some pink Anguloa uniflora lurking somewhere in its pedigree. Regardless, it's a beautiful plant. There are a dozen or so species of Anguloa native to the Andean tropics. They are among the most beautiful orchids in our collection.

Monday, October 27, 2014

How to Repot an Orchid

Yes, you can do this. It's not rocket science. Repotting is fun. And your orchid will thank you, especially if it's been two or more years since it was repotted. Never repotted an orchid before? We can fix that. Come on into our greenhouse and I'll show you how.

1. Gather your materials.  A good basic orchid mix consists of equal parts fir bark, charcoal and sponge rock (aka coarse perlite). You can buy these products online from OFE International and Tropical Plant Products. They also sell high quality ready-to-use packaged orchid mixes. Grower's Tip: The organic component -in this case the bark- can make or break the quality of an orchid mix, because that's the part that breaks down with repeated watering. The bark should be Douglas Fir or Pinus radiata, and should be mold-free. Pinus radiata (sold as Orchiata) and kiln-dried Douglas Fir bark (sold as Rexius bark) last longer than regular Douglas Fir bark. Fir bark often needs to be rinsed beforehand in order to remove dust and sediment.

2. Select a plant. The best time to repot an orchid like Cattleya is when the new shoot is about the length of your pinkie finger. The new shoot indicates that the plant has started a new cycle of growth, the perfect time to provide new roots with fresh medium. We repot every two years, because that's the lifetime of fir bark mixes in our greenhouse. Any longer is asking for trouble -a waterlogged mix that kills roots. Grower's Tip: Keep your eye on that new shoot while repotting! It is as fragile as new asparagus and if you break it, you lose an entire season's growth, including the flowers.

3. Invert the plant, tap the rim of the pot against the table and remove the plant. Keep the new shoot well away from the table when you do this. Grower's Tip: Water your plant the day before to make it easier to dislodge.

4. Remove the old mix. Hold the plant by the pseudobulbs (not the roots!) with one hand and gently prod the mix with your other hand in order to loosen it. Grower's Tip: Expect to find new yellow-tipped roots emerging near the base of the new shoot. Be careful not to break them.

5. Remove the dead roots. Healthy roots are white and firm. Dead roots are grey/black and squishy. You can use pruners for cutting, but remember that viruses in plant sap can be spread by using the same tool on consecutive plants. Grower's Tip: That's why we use one razor blade per plant. We wrap used blades in duct tape before discarding them. When I divide a large plant, I use a kitchen knife and sterilize it with a propane torch between plants. Grower's Tip #2: Notice the new shoot face up on the table? Don't rest the plant on its new shoot. Grower's Tip #3: Orchid roots can absorb tannins from the bark in the mix and appear brown on the surface. A brown root can be healthy. When in doubt, cut a cross section--a healthy root will have a white core.

6. Wash the roots. I like to do this under a gentle stream of water at the sink. It gently removes the old bark hiding in inaccessible places. And it often reveals more dead roots that need to be cut away. If the roots are healthy you don't need to remove all the mix --only about three quarters. If the roots are in poor shape, remove as much old mix as possible. Grower's Tip: This is a great time to observe how your plant is constructed. Notice how the vertical shoots (the pseudobulbs) are connected by a horizontal stem (or rhizome, pronounced rye-zome). This will become important in a few minutes.

7. Choose a pot size based on the size of the root mass, not the top growth. One inch bigger all around is plenty. Orchids like to attach their roots to their surroundings. Let them. Grower's Tip: A step up in pot size isn't always necessary. Sometimes fresh mix and a clean pot of the same size is all that's needed.

8. Center the new shoot in the pot. See how I'm holding the older part of the plant against the rim of the pot? That's because I want the new shoot in the center where it will have plenty of room to grow over the next two years. Looks asymmetric, right? Absolutely. The new shoot goes in the center. Hold the base of the new shoot about a half inch below the top rim. That's your imaginary fill line.

9. While holding the plant in place with your left hand, add mix with your right hand, small amounts at a time.

Wednesday, October 8, 2014

Stanhopea connata

Stanhopea connata ABG# 1993-2450
Not every Stanhopea smells like a pastry shop. Poor Stanhopea connata. It's the one Stanhopea that can clear a room.
Dorsal view of Stanhopea connata ABG# 1993-2450
While most stanhopeas have fragrances delectable enough to eat, Stanhopea connata exudes cresole and indole. Cresole is the fragrance compound associated with coal tar (think freshly poured asphalt). And indole has a fragrance described in botanical literature as fecal. I was not, to be honest, in a hurry to have a closed door photo session with Stanhopea connata.
Front view of Stanhopea connata
And that's too bad! Look at that face, with the bold tiger stripes and spots. I was completely charmed. Charmed and overwhelmed, actually.
Dorsal view of the lip and column with sepals and lateral petals removed 
Of course, it doesn't matter one bit what I think of the fragrance. The fragrance is all about attracting a pollinator. And it's kind of cool to think that there are fragrance-collecting bee species in the tropics who are mad for asphalt and cow dung.
Dorsal view of the lip without the column
My photo shoot with S. connata lasted about an hour. Over time, the cresole seemed to diminish and the indole began to assert itself. But by the end I hardly noticed. What a handsome plant this is. The images will be stored in ABG's image library.
Ventral view of the lip
Stanhopea connata grows as an epiphyte along the eastern cordillera in Peru, Colombia and Ecuador. It is pollinated by Eulaema speciosa.
Ventral view of the column

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